The disclosure generally relates to a power converter and, more particularly, to a control circuit and related method for improving the stability of the output signal of the power converter.
In a conventional power converter, a feedback circuit is employed to generate a feedback signal corresponding to the magnitude of an output signal of the power converter. A control circuit of the power converter typically utilizes a comparing circuit to compare the feedback signal with a reference signal to generate a comparison signal. A control signal generating circuit of the control circuit generates the control signal (e.g., the PWM signal) for controlling the operations of the power switch based on the comparison signal.
However, in the applications where the equivalent series resistance on an output capacitor of the power converter is small or the voltage-dividing ratio of the feedback circuit is small, the feedback signal generated by the feedback circuit would have a small magnitude. In this situation, noise occurring in the power converter easily causes the comparing circuit to operate erroneously and thus results in jitters in the comparison signal, thereby causing the output signal of the power converter to be unstable.